The invention concerns an automatic stainer for staining specimens that are arranged on specimen slides and embedded in a medium, preferably in paraffin, in which multiple reagent containers arranged one behind another are provided for treating the specimens, and the specimen slides pass successively through the reagent containers; having a transport basket for receiving multiple specimen slides, such that multiple transport baskets can be received simultaneously each in different reagent containers; and having a motorized transport mechanism with a lifting device that lifts all the transport baskets simultaneously out of the respective reagent container and transports them on into the respective adjacent reagent container.
The histological specimens provided for microscopic examination are placed onto specimen slides after being cut with a microtome. The specimen slide is then appropriately labeled and cataloged. To increase contrast for a subsequent microscopic examination, these specimens are then stained, making the structures in the cells or the tissues visible in differentiated fashion. In addition to various special stains, one standard staining process has become established in practical use. In this xe2x80x9chematoxylin-eosinxe2x80x9d staining method, the specimens pass through different processing stages with xylene, alcohol, eosin, hematoxylin, acetic acid, and water. Various types of automatic stainers, which automatically convey the specimens to the respective processing stages, are used to stain the specimens.
Automatic stainers with a simplified transport mechanism and a high preparation throughput are offered by the company styled xe2x80x9cmeditexe2x80x9d under the designation xe2x80x9cCOT 20,xe2x80x9d and by the company styled xe2x80x9cSakuraxe2x80x9d under the designation xe2x80x9cLinear Slide Stainer II.xe2x80x9d Both automatic stainers operate on the principle of a continuously recirculating transport motion for the transport baskets in which the specimen slides with the specimens are located. During the transport motion, the transport baskets are transported, at constant cycling times, into the reagent containers arranged one behind another. Any necessary residence time for the specimens in the respective containers is achieved using multiple reagent containers arranged one behind another. The transport basket is suspended in a transport rail, and conveyed by the transport rail a specific distance to the next reagent container where it is lowered again. The transport rail travels beneath the support bracket of the transport basket back into its starting position. Another transport basket can now be placed onto the transport rail. Once a predefined time interval has elapsed, the transport rail simultaneously lifts up all the transport baskets present in the automatic stainer, and transports them into the next reagent containers.
Before the specimens (usually embedded in paraffin) can be subjected to treatment in an automatic stainer of this kind, the embedding medium (in this case paraffin) must be gently removed. Otherwise the risk exists that the staining solutions will not be able to penetrate into the tissue. For this reason, before treatment the specimen slides are heated in a separate oven until the paraffin present on the specimen slides has vaporized or melted.
The separate oven makes an additional manual process step necessary in this case. The risk also exists, when the heated specimen slides are being handled, that the operator may be burned and that hot specimen slides may be dropped upon removal.
It is therefore the object of the present invention to further develop a known automatic stainer in such a way that no additional manual working steps are necessary in order to remove the embedding medium prior to staining of the specimen.
This object is achieved, according to the present invention, by the features recited herein.
The automatic stainer is characterized in that a heating station for heating the specimens and melting the embedding medium is arranged in front of the row of reagent containers and is integrated into the transport mechanism, and the heating station has at least one melting container for simultaneously receiving multiple transport baskets.
In an embodiment of the invention, the heating station has an oven housing which is equipped with a fan and an electric heating package. Instead of a fan, it is of course also possible to provide a fluid which is heated by the heating package.
An air distributor, which directs the heated air via an opening in the wall or the floor of the melting container onto the specimen slides, can be provided in the oven housing.
In a further embodiment of the invention, the temperature inside the heating station can be adjusted by way of a controller. If multiple melting containers arranged next to one another are present in the heating station, the temperature in each melting container can be adjusted separately by way of the controller.
The lifting device can be equipped with two transport rails, arranged parallel to one another, which are each equipped with a transport notch in the region of the reagent containers, and with a sawtooth profile in the region of the heating station. As a result, in the region of the reagent containers the transport baskets are transported on into the respective adjacent reagent container with one transport stroke, the transport baskets simultaneously traveling a shorter distance in the region of the heating station. The sawtooth profile is configured in such a way that the brackets of the transport baskets, when lifted, slide down on the flanks of the profile and are entrained only by the shoulder.
In an embodiment of the invention, two support rails equipped with grooves are arranged in the region of the heating station, parallel to the transport rails, as a support for the brackets of the transport baskets.
The spacing between adjacent grooves can be half as great as the spacing between the individual reagent containers arranged one behind another.
In the case of the sawtooth profile, the slope of the flanks and their spacing from one another can be such that in the region of the heating station, each transport basket is conveyed into the adjacent groove with one transport stroke.
Advantageously, the heating station is configured as a separate and retrofittable module.